1. Field of the Invention
The invention relates to a communication apparatus, a communication system, and a communication method.
2. Description of the Related Art
In one-to-one communication in a traditional communication system, a transmitting terminal transmits data of one frame and a receiving terminal transmits an ACK signal confirming correct receipt of the frame and data to the transmitting terminal. If the data is not correctly received, the receiving terminal transmits a NACK signal. After correctly receiving an ACK signal from the receiving terminal, the transmitting terminal transmits data of the next frame to the receiving terminal. When a NACK signal is received from the receiving terminal, or an ACK signal has not been correctly received or received during a predetermined time period, the data that has already been transmitted is retransmitted.
In one-to-many communication in a traditional communication system, a single transmitting terminal transmits data to a plurality of receiving terminals; the transmitting terminal transmits the data to the receiving terminals using identifying (ID) information for each of the receiving terminals. A receiving terminal checks whether the ID information is correct and receives the data when the ID information is correct. Otherwise, the receiving terminal disposes of the received data.